Compound of formula-I wherein R1 is methoxymethyl (MOM), R2 is ethyl, Y is oxygen atom and X is hydroxyl or bromo is used by Jieping Zhu, et al in their synthesis of Ecteinascidin 743 (J. Am. Chem. Soc., 2006, 128, pages 87-89). According to the process given in this reference, sesamol is protected with methoxymethyl group and converted to compound of formula-III by reacting with n-butyl lithium and trimethyl borate (Scheme-I). Compound of formula-III is reacted with ethyl glyoxalate in the presence of hexafluoroisopropanol to get the compound of formula-IV. Triflation of compound of formula-IV followed by reaction with trimethylboroxine in the presence of palladium (tetrakis-triphenylphosphine) gave the compound of formula-VI. Reaction of compound of formula-VI with thionyl bromide gave the compound of formula-VII. Compound of formula-VII is used as a key intermediate in the synthesis of Ecteinascidin 743.

Main drawback in this process is the handling of costly, toxic, and pyrophoric reagents. Another main drawback in the synthesis is the non-availability of trimethylboroxine on commercial scale.
Keeping in view of the difficulties in commercialization of the above-mentioned process for the preparation of compound of formula-I, we aimed to develop a simple, economical, and commercial process.
We observed that a promising approach for a process for the preparation of compound of formula-I would be to (a) avoid the usage of costly and difficult to handle reagents.
Accordingly, the main objective of the present invention is to provide an improved process for the preparation of compound of formula-I, which is commercially applicable.